1. Field of the Invention
The present invention relates to a medical image part recognition apparatus for performing part recognition of a body shown in a medical image based on image data acquired by a medical imaging modality, and a medical image part recognition program to be used in the apparatus.
2. Description of a Related Art
Recent years, many medical images showing the interiors of living bodies have been used in medical diagnoses, and, in order to acquire such medical images, various technologies and apparatuses (modalities) such as an X-ray imaging apparatus, an X-ray CT (computed tomography) apparatus, a US (ultrasonic) diagnostic apparatus, an MRI (magnetic resonance imaging) apparatus, and a PET (positron emission tomography) apparatus are widely used. Many of the apparatuses are digitalized, and diagnostic information processing systems within hospitals and so on are being constructed. Further, among the imaging technologies, CT and MRI have achieved significant results in detection and evaluation of lesion parts in living bodies because they can acquire and display axial images of a living body at relatively short intervals. Here, an axial image refers to a tomographic image that shows a surface perpendicular or nearly perpendicular to the body axis of an object to be inspected or a so-called cross sectional surface. Hereinafter, the axial image is also simply referred to as “slice image”.
At the time of tomographic imaging for CT inspection or the like, not only one part (e.g., only the chest or the abdomen) is necessarily imaged, but also imaging is often performed over plural parts (e.g., from the chest to the abdomen, from the head to the chest, or the like) in one inspection. On the other hand, thus obtained one series of slice images are typically displayed on a screen sequentially along a direction in which the imaging has been performed. Accordingly, a doctor, who observes the slice images and makes a diagnosis, must begin image interpretation from seeking an image showing the part as an object of the diagnosis. However, one series of images typically contains a thousand and several hundreds of images to several thousands of images, and therefore, significant effort and burden are imposed on the image interpretation doctor. On this account, an apparatus, system, or the like is desired that can promptly display an image showing a desired part among an enormous amount of images with less effort.
As a related technology, Japanese Patent Application Publication JP-P2002-253539A discloses a medical image identification system for enabling efficient management of an enormous amount of medical images by automatically extracting imaging attribute information of imaging apparatus, part, imaging orientation, and so on from medical images by image processing, and adding the information to management information. The medical image identification system is a system for storing and managing medical images, and includes means for classifying an input image, template image storing means for storing template images on categories to be identified with respect to the classification, means for selecting template images of plural categories as candidates of identification by using the classification result of the input image, image identifying means for comparing the selected template images with the input image and determining the category of the template image that is the best match, and means for adding manage information of the template image to manage information of the input image. That is, according to JP-P2002-253539A, the imaging part or the like of the input image is determined by classifying the input image based on the size of the input image, the number of rectangular areas in the input image, and so on, selecting template images of plural categories based on the classification, extracting one that matches the gray scale information and the mosaic image of the input image from the selected template images, and providing the management information (e.g., the imaging part) that has been provided to the template image as management information of the input image.
However, one medical image does not always show only one part. For example, plural parts are often shown in the way that the chest is shown in a portion of an image and the abdomen is shown in another portion of the image. Despite this, JP-P2002-253539A discloses nothing about part recognition for images that show plural parts.
Further, Japanese Patent Application Publication JP-P2003-10166A discloses an image processing apparatus for performing optimum image processing on image data according to imaging direction and/or imaging part even when imaging information representing the imaging direction and/or imaging part is not provided to the image data. The image processing apparatus includes determining means for determining whether or not imaging information representing imaging direction and/or imaging part at the time of taking a medical image is provided to medical image data representing the medical image, recognizing means for recognizing the imaging direction and/or imaging part based on the medical image data when the imaging information is not provided, and providing means for providing to the medical image data the recognition result as the imaging information. According to JP-P2003-10166A, recognition of an imaging part is performed by utilizing an intrinsic image created by using plural image data in advance.
However, in JP-P2003-10166A, the part recognition only for one image is performed.